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|
/*
* drivers/rtc/rtc-spear.c
*
* Copyright (C) 2010 ST Microelectronics
* Rajeev Kumar<rajeev-dlh.kumar@st.com>
*
* This file is licensed under the terms of the GNU General Public
* License version 2. This program is licensed "as is" without any
* warranty of any kind, whether express or implied.
*/
#include <linux/bcd.h>
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/irq.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/rtc.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
/* RTC registers */
#define TIME_REG 0x00
#define DATE_REG 0x04
#define ALARM_TIME_REG 0x08
#define ALARM_DATE_REG 0x0C
#define CTRL_REG 0x10
#define STATUS_REG 0x14
/* TIME_REG & ALARM_TIME_REG */
#define SECONDS_UNITS (0xf<<0) /* seconds units position */
#define SECONDS_TENS (0x7<<4) /* seconds tens position */
#define MINUTES_UNITS (0xf<<8) /* minutes units position */
#define MINUTES_TENS (0x7<<12) /* minutes tens position */
#define HOURS_UNITS (0xf<<16) /* hours units position */
#define HOURS_TENS (0x3<<20) /* hours tens position */
/* DATE_REG & ALARM_DATE_REG */
#define DAYS_UNITS (0xf<<0) /* days units position */
#define DAYS_TENS (0x3<<4) /* days tens position */
#define MONTHS_UNITS (0xf<<8) /* months units position */
#define MONTHS_TENS (0x1<<12) /* months tens position */
#define YEARS_UNITS (0xf<<16) /* years units position */
#define YEARS_TENS (0xf<<20) /* years tens position */
#define YEARS_HUNDREDS (0xf<<24) /* years hundereds position */
#define YEARS_MILLENIUMS (0xf<<28) /* years millenium position */
/* MASK SHIFT TIME_REG & ALARM_TIME_REG*/
#define SECOND_SHIFT 0x00 /* seconds units */
#define MINUTE_SHIFT 0x08 /* minutes units position */
#define HOUR_SHIFT 0x10 /* hours units position */
#define MDAY_SHIFT 0x00 /* Month day shift */
#define MONTH_SHIFT 0x08 /* Month shift */
#define YEAR_SHIFT 0x10 /* Year shift */
#define SECOND_MASK 0x7F
#define MIN_MASK 0x7F
#define HOUR_MASK 0x3F
#define DAY_MASK 0x3F
#define MONTH_MASK 0x7F
#define YEAR_MASK 0xFFFF
/* date reg equal to time reg, for debug only */
#define TIME_BYP (1<<9)
#define INT_ENABLE (1<<31) /* interrupt enable */
/* STATUS_REG */
#define CLK_UNCONNECTED (1<<0)
#define PEND_WR_TIME (1<<2)
#define PEND_WR_DATE (1<<3)
#define LOST_WR_TIME (1<<4)
#define LOST_WR_DATE (1<<5)
#define RTC_INT_MASK (1<<31)
#define STATUS_BUSY (PEND_WR_TIME | PEND_WR_DATE)
#define STATUS_FAIL (LOST_WR_TIME | LOST_WR_DATE)
struct spear_rtc_config {
struct rtc_device *rtc;
struct clk *clk;
spinlock_t lock;
void __iomem *ioaddr;
unsigned int irq_wake;
};
static inline void spear_rtc_clear_interrupt(struct spear_rtc_config *config)
{
unsigned int val;
unsigned long flags;
spin_lock_irqsave(&config->lock, flags);
val = readl(config->ioaddr + STATUS_REG);
val |= RTC_INT_MASK;
writel(val, config->ioaddr + STATUS_REG);
spin_unlock_irqrestore(&config->lock, flags);
}
static inline void spear_rtc_enable_interrupt(struct spear_rtc_config *config)
{
unsigned int val;
val = readl(config->ioaddr + CTRL_REG);
if (!(val & INT_ENABLE)) {
spear_rtc_clear_interrupt(config);
val |= INT_ENABLE;
writel(val, config->ioaddr + CTRL_REG);
}
}
static inline void spear_rtc_disable_interrupt(struct spear_rtc_config *config)
{
unsigned int val;
val = readl(config->ioaddr + CTRL_REG);
if (val & INT_ENABLE) {
val &= ~INT_ENABLE;
writel(val, config->ioaddr + CTRL_REG);
}
}
static inline int is_write_complete(struct spear_rtc_config *config)
{
int ret = 0;
unsigned long flags;
spin_lock_irqsave(&config->lock, flags);
if ((readl(config->ioaddr + STATUS_REG)) & STATUS_FAIL)
ret = -EIO;
spin_unlock_irqrestore(&config->lock, flags);
return ret;
}
static void rtc_wait_not_busy(struct spear_rtc_config *config)
{
int status, count = 0;
unsigned long flags;
/* Assuming BUSY may stay active for 80 msec) */
for (count = 0; count < 80; count++) {
spin_lock_irqsave(&config->lock, flags);
status = readl(config->ioaddr + STATUS_REG);
spin_unlock_irqrestore(&config->lock, flags);
if ((status & STATUS_BUSY) == 0)
break;
/* check status busy, after each msec */
msleep(1);
}
}
static irqreturn_t spear_rtc_irq(int irq, void *dev_id)
{
struct spear_rtc_config *config = dev_id;
unsigned long flags, events = 0;
unsigned int irq_data;
spin_lock_irqsave(&config->lock, flags);
irq_data = readl(config->ioaddr + STATUS_REG);
spin_unlock_irqrestore(&config->lock, flags);
if ((irq_data & RTC_INT_MASK)) {
spear_rtc_clear_interrupt(config);
events = RTC_IRQF | RTC_AF;
rtc_update_irq(config->rtc, 1, events);
return IRQ_HANDLED;
} else
return IRQ_NONE;
}
static int tm2bcd(struct rtc_time *tm)
{
if (rtc_valid_tm(tm) != 0)
return -EINVAL;
tm->tm_sec = bin2bcd(tm->tm_sec);
tm->tm_min = bin2bcd(tm->tm_min);
tm->tm_hour = bin2bcd(tm->tm_hour);
tm->tm_mday = bin2bcd(tm->tm_mday);
tm->tm_mon = bin2bcd(tm->tm_mon + 1);
tm->tm_year = bin2bcd(tm->tm_year);
return 0;
}
static void bcd2tm(struct rtc_time *tm)
{
tm->tm_sec = bcd2bin(tm->tm_sec);
tm->tm_min = bcd2bin(tm->tm_min);
tm->tm_hour = bcd2bin(tm->tm_hour);
tm->tm_mday = bcd2bin(tm->tm_mday);
tm->tm_mon = bcd2bin(tm->tm_mon) - 1;
/* epoch == 1900 */
tm->tm_year = bcd2bin(tm->tm_year);
}
/*
* spear_rtc_read_time - set the time
* @dev: rtc device in use
* @tm: holds date and time
*
* This function read time and date. On success it will return 0
* otherwise -ve error is returned.
*/
static int spear_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
struct spear_rtc_config *config = dev_get_drvdata(dev);
unsigned int time, date;
/* we don't report wday/yday/isdst ... */
rtc_wait_not_busy(config);
time = readl(config->ioaddr + TIME_REG);
date = readl(config->ioaddr + DATE_REG);
tm->tm_sec = (time >> SECOND_SHIFT) & SECOND_MASK;
tm->tm_min = (time >> MINUTE_SHIFT) & MIN_MASK;
tm->tm_hour = (time >> HOUR_SHIFT) & HOUR_MASK;
tm->tm_mday = (date >> MDAY_SHIFT) & DAY_MASK;
tm->tm_mon = (date >> MONTH_SHIFT) & MONTH_MASK;
tm->tm_year = (date >> YEAR_SHIFT) & YEAR_MASK;
bcd2tm(tm);
return 0;
}
/*
* spear_rtc_set_time - set the time
* @dev: rtc device in use
* @tm: holds date and time
*
* This function set time and date. On success it will return 0
* otherwise -ve error is returned.
*/
static int spear_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
struct spear_rtc_config *config = dev_get_drvdata(dev);
unsigned int time, date;
if (tm2bcd(tm) < 0)
return -EINVAL;
rtc_wait_not_busy(config);
time = (tm->tm_sec << SECOND_SHIFT) | (tm->tm_min << MINUTE_SHIFT) |
(tm->tm_hour << HOUR_SHIFT);
date = (tm->tm_mday << MDAY_SHIFT) | (tm->tm_mon << MONTH_SHIFT) |
(tm->tm_year << YEAR_SHIFT);
writel(time, config->ioaddr + TIME_REG);
writel(date, config->ioaddr + DATE_REG);
return is_write_complete(config);
}
/*
* spear_rtc_read_alarm - read the alarm time
* @dev: rtc device in use
* @alm: holds alarm date and time
*
* This function read alarm time and date. On success it will return 0
* otherwise -ve error is returned.
*/
static int spear_rtc_read_alarm(struct device *
|